You’ll have to have an ambivalent attitude towards the paintwork on your car as it will take the odd chunk out, either at the roof or bumper. Also there will be one time you open the boot, forget the empty carrier is on, then said boot lowers rather more rapidly than planned!
Bit of a burden when off the car. Fitting and removal easy once you’ve got the hang of it, but not something you’ll do for pleasure.
Roof rack much better, but better still are the tow bar mounted ones.
Thule roof racks are modular, so you may only need to buy different foot pads between the cars. In any case there’s a healthy eBay market so you don’t need to buy new. Just get the required codes from Halfords…. Roof bars easy to store when off the car.